Studies on the mechanisms that detoxify chemicals and protect cells against toxicity, mutagenicity and cancer are highly significant for human health. Two cytosolic proteins [NAD(P)H:quinone oxidoreductase1(NQO1) and NRH:quinone oxidoreductase2 (NQO2)], with the function of quinone detoxification, were cloned. NQO1-/- and NQO2-/- mice were produced using targeted gene disruption. These mice were born and reproduced normal. However, NQO1-/- mice were shown to exhibit altered intracellular redox status and reduction in abdominal adipose tissue, interstitial cystitis of bladder, myelogenous hyperplasia and B cell deficiency in blood. NQO2-/- mice also showed myelogenous hyperplasia and B cell deficiency. NQO1-/- and NQO2-/- mice showed differential response to menadione induced hepatic damage indicating a role of NQO1 in detoxification and NQO2 in activation of menadione. NQO1-/- and NQO2-/- mice also demonstrated increased susceptibility to develop dimethy1 benzanthracene (DMBA) and benzo(a)pyrene (BP) induced skin tumors as compared with the wild type mice. Studies also showed that reduced levels of p53 and decreased apoptosis contributed to myelogenous hyperplasia and increased susceptibility to develop BP-induced skin tumors. NQO1-/- and NQO2-/- mice were cross-bred to generate double knockout mice deficient in both NQO1 and NQO2. The major goals of this proposal are to investigate the mechanism and in vivo function of NQO1 and NQO2 in protection against interstitial cystitis and leukemia, immune response and autoimmunity, and susceptibility to chemical carcinogenesis. First aim will characterize double knockout mice, determine its sensitivity to menadione induced toxicity and investigate the mechanism of the role of NQO1 in protection against interstitial cystitis. Second aim will investigate the in vivo role and mechanism of the role of NQO1 and NQO2 in radiation and benzene induced leukemia, immune response and autoimmunity. Third aim will elucidate the in vivo role and mechanism of the role of NQO1 and NQO2 in protection against chemical induced skin and internal organ carcinogenesis. To this effect, double knockout mice will be analyzed for accumulation of NAD(P)H/NRH, alterations in intracellular redox status and accumulation of abdominal adipose tissue, myelogenous hyperplasia and menadione induced hepatic damage. Tissues histology will study lesions in various tissues. Wild type, NQO1-/-, NQO2-/- and double knockout mice will be exposed to radiation and benzene to study susceptibility to develop leukemia and to alum-precipitated NP (4-hydroxy-3-nitrophenyl)acetyl conjugated to CGG (chicken ?-globulin) and NP-CGG to study primary and secondary immune response and to collagen to study autoimmunity. Cytogenetic assays will identify chromosomal translocations. Skin and internal organ carcinogenesis models will study susceptibility of double and individual knockout mice to DMBA and BP induced carcinogenesis. Western, immunoprecipitation, microarrays and proteomic assays will elucidate the role of NQO1 and NQO2 in regulation of p53 and apoptosis/growth/differentiation factors in protection against interstitial cystitis, radiation induced leukemia and BP induced skin carcinogenesis